Stop motion for knitting machines



Jan. 30, 1945. J w c s I 2,368,184

STOP MOTION FOR KNITTING MACHINES Filed June 18, 1943 21 inql- 2 T I Q EIQL 4 2? 46 M g 39 I 38 F 2 37 7 21 /26 5 40 1 7 inc 21 luq ' 'INVENTOR. JACOB WMHS/WM Patented Jan. 30, 1945 UNITED STATES PATENT orrlcs STOP MOTION FOR KNITTING MACHINES Jacob Wachsman, Brooklyn, N. Y. Appllcation June 18, 1943, Serial No. 491,292 66-157) 1 Claim.

The object of this invention is to provide a generally improved stop motion for knitting machines of the type shown in my Patent 2,222,325 of November 20, 1940. One object of the invention is to provide a device having but very few parts whereby to reduce the cost of manufacture and obtaingreater eillciency. Another object is to include in the invention means whereby the device may be automatically operated by actuation from the take up mechanism oi the knitting machine. In the accompanying drawing,

Fig. 1 is a front view of the stop motion with parts removed and parts broken away.

Fig. 2 is a sectional View taken on the line 2-2 of Fig. 1.

Fig. 3 is a sectional view on the line 33 of Fig. 1.

Fig. 4 is a diagram illustrating the operation of the device.

Referring first to Fig. 4 the numeral l0 indicates conventionally the stop handle of a knitting machine drive. When the handle is swung on its pivot the driving mechanism, not shown, is operated to stop the machine, the operation being similar to that of a belt shifting mechanism. The operation of the stop handle is controlled by a travelling thread. The control mechanism is in the form of a switch in which a movable member ii is supported on the thread i2 which runs over guides it. When the thread breaks or runs out the member ll drops and makes contact with a fixed member iii to close a normally open electric circuit. The member it is grounded as indicated. The movable member H, which sometimes is called an end detector or a knot detector, is connected to a battery it, an electromagnet it and a contact spring ll. The latter is normally grounded by contact with a movable plunger it which actuatesthe handle M. The magnet has a pivoted armature iii which is attracted when the magnet is energized by closure of the electric circuit. This occurs when the thread it fails to keep the switch N i l open. Normally the plunger is prevented from operating the stop handle by means of a stop lever, not shown in Fig. and which will be explained later. Such stop lever in turn is held inposition to. prevent ported within a box 28 which is adapted to be mounted upon the knitting machine with the plunger H3 in position to engage the stop handle ill of the machine as will be understood. The box is closed by a cover 21. The magnet is is mounted at one end of the box. One end of the magnet wiring is connected to a fixed terminal 34 tor-attaching the wire from the batter I5. The other end of the magnet wiring is connected to the spring I! for grounding the circuit on the machine. The plunger I8 is slidably mounted in the ends of the box 26 in cut out guide bearings 28, 2B. The plunger carries a block 29 which forms a contact finger 30 which is normally engaged by the spring II. The block also forms an arm 3! with a branch finger 32 adapted to engage a stop lever 38. The latter is a fiat piece which extends longitudinally of the box. One end of the stop lever is pivoted on a right angled bolt 39. The other free end of the stop lever, to the left in Figs. 1 and 3, is engaged by a finger 31 which extends from the armature l9, Fig. 2.

The stop lever 38 is cut out to provide two in clined hooks 40 and 4|. Normally the hook 40 is engaged by the said finger 32 on the block 29 under pressure of a spring 38 which is borne by the plunger is and which spring operates between one end of the box and the said block 29. The spring normally urges the plunger outward from the box to operate the handle Ill. The plunger is normally prevented from so moving by the said finger 32 which lies across the stop lever 88 and is held there by the spring 33 in engagement with the hook 40, that is in engagement with the stop lever 38.

Normally the finger 82 Dresses hard against the hook ill and seeks to push the stop lever 38 aside by swinging it about the lever pivot 39 into the dotted position shown in Fig. 3. The hook to is a mere low slightly inclined edge and unless the lever 38 is held by some other means, the finger 32 will jump the hook and thus release the stop lever. When thatoccurs there is nothing to prevent the plunger from being operated by the spring 33. However, so long as the free end of the stop lever is is engaged by the armature fin ger 3! the stop lever cannot move. The moment the armature finger S'l is disengaged from the stop lever, the finger 32 will jump the hook t6 and the plunger will be released.

The movement of the plunger i8 is in the nature of a quick hard blow caused by the force of the spring 33. The movement of the plunger is cushioned by a spring 50 which acts between the other end of the box and the block 29. The armature is held away from the magnet against a stop it by a spring I. The stop lever 38 is'inclined as at 43 downward towards the hook II to facilitate the straight line movement of the finger 32. The plunger is moved back into normal position within the box by the operator. At the end of this manual resetting movement of the mechanism the finger 32 hits the hook ll with a hard blow thereby moving the stop lever back into normal position. At the same time also the circuit is again grounded at "-30. A guide ill within the box prevents the stop lever from movement in any plane but its own.

Operation-The parts are shown in their normal positions in the drawing. The stop lever is is under constant pressure by the spring actuated nnger 32 which therefore seeks to jump the hook to release the stop lever. The armature linger 81 prevents such movement. But when the circuit is closed the support of the armature finger is withdrawn from the stop lever. The latter is moved to one side by. the flnger 32 and the plunger is released to be operated by the spring ll. Resetting the plunger puts the parts back into normal positions. The box cover 21 is held in position by a screw 44, Fig. 2, which enters a hole 45 in the wall of the box, Fig. 1. The cover is also held by reason of the fact that one branch of the right angled bolt 39 .passes through the cover, Fig. 3, and serves as a screw for a nut 46 to secure the cover. The pivot bolt 39 thus serves two purposes. A characteristic feature of the invention resides in the fact that the armature l8 may be operated mechanically by a pin 20 seated in the cover of the box and which pin is adapted to be depressed by a pivoted lever 2| which is connected at 22 to the take up mechanism 23 of the knitting machine. This mechanism is indicated diagrammaticaliy by the usual take up guiding rollers 24, 24 which guide the fabric 25 as it comes down from the knitting mechanism, not shown. When for any reason the latter mechanism fails in its aseanae normal operation, the take up mechanism will fall down or move down so that the lever-2| will be moved down to eng ge and depress the pin 20. The armature I! will then be operated mechanically to lower the finger 31 away from the end of the stop lever 8| after which the stop motion will be operated the sameas when the magnet were energized to attract the armature.

' The lever 2| is normally urged upward by a spring l2 to provide against sudden drops and to include a certain resiliency in the movements of the lever.

From the foregoing it will be clear that the stop motion is operated automatically to cause st ppage of the knitting machine both when a travelling thread fails to keep the electric circuit open and also when the take up mechanism moves down due to some failure of some other part of the machine connected to the take up mechanism. The invention thus provides both electrical and mechanical operation.

I claim:

In a stop motion for knitting machines which include a fabric take up mechanism and an electric circuit with a normally open switch controlled by a travelling thread, said stop motion including a stop handle, a plunger for actuating the stop handle, a spring for moving said plunger to actuate said handle, a pivoted stop lever, means on the stop lever engaging said plunger to hold the same immovable against the action of the said spring, a projecting finger engaging said stop lever to hold the same in operative engagement with said plunger, an electromagnet in said circuit for operating the said finger to release the said stop lever when said circuit is no longer under the control of the travelling thread, a pin for operating said projecting finger independent of the operation thereof by said magnet and means connected to and operated by the said fabric take up mechanism for actuating said pin when the said take up mechanism moves into a predetermined abnormal position.

JACOB WACHSMAN. 

